In the field of telecommunications numerous customers are connected with the switch or other equipment like line terminating equipment or multiplex systems (e.g. a Digital Subscriber Line Access Multiplex, DSLAM) of a telecommunications company via telecommunication lines. Between the customer and the switch or other equipment sections of the telecommunication lines are connected with connection points, such as terminal modules. The terminal modules establish an electrical connection between a wire, which is connected to the terminal module at a first side, and another wire, which is connected to the terminal module at a second side. There is sometimes a need to carry out measurements for the connection thus established. Measurements can be made, for example, between the telephone connection of a customer and the switch of the telecommunications company. Such measurements serve, to test the connection in general, or to localize any disturbances which may have occurred.
In this context, WO 03/079599 assigned to the applicant, discloses a so-called contact bank as well as circuits for providing test and/or monitoring access to telecommunication lines. In particular, the circuit can comprise a bus and several stub wires. The stub wires lead to the telecommunication lines that are to be tested. Any stub wires which are not in use can be disconnected from the bus. However, also in this disconnected state the stub wires act as antennas and may deteriorate the result of the measurements. In particular, the problem underlying the invention described below cannot be solved by the known circuit.